Hi Nadia
I think you could achieve something close in Storyline 360 Beta. It has a new Emphasis animation. One of the animation options is zoom.
You could create or crop the zoom area (part of the image) to its needed size and lay it on top of its matching background. This top element is "invisible" to the naked eye.
Next, add a trigger such as Emphasize with Zoom when learner hovers or drags item (magnifying glass labeled "Drag") over "Zoom Area".
I tried something similar last night when I was playing around.
If you aren't able to switch to beta, you can create this effect manually in Storyline 360. Instead of the new animation (Emphasis), you would create the Zoom effect on a separate layer by adding the "Entrance Zoom" animation to the state of the cropped element. Then add a "Change State to Zoomed" when item (Drag item) hovers over (Zoomed Area) which is the cropped element.
Hope this helps.